Finding the Fourth Proportional to 89.78, 123.86 and 62.10

Step by Step Solution

1. Step 1: Write the proportion equation
   89.78 : 123.86 = 62.10 : x
2. Step 2: Convert to fraction form
   89.78/123.86 = 62.10/x
3. Step 3: Cross multiply
   89.78x = 123.86 × 62.10
4. Step 4: Simplify right side
   89.78x = 7,691.71
5. Step 5: Solve for x
   x = 7,691.71/89.78
6. Step 6: Final answer
   x = 85.67